Rapamycin Plays a Pivotal Role in the Potent Antifungal Activity Exhibited Against Verticillium dahliae by Streptomyces iranensis OE54 and Streptomyces lacaronensis sp. nov. Isolated from Olive Roots

[EN] Verticillium wilt, caused by Verticillium dahliae, poses a significant threat to olive trees (Olea europaea L.). The isolation of endophytic Streptomyces strains from olive roots has led to the discovery of several strains showing strong antifungal activity against V. dahliae, as demonstrated t...

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Detalles Bibliográficos
Autores: Calvo Peña, Carla, Ruiz Muñoz, Marina, Nouioui, Imen, Kirstein, Sarah, Neumann-Schaal, Meina, Sánchez López, José María, Ghoreshizadeh, Seyedehtannaz, Cobos Román, Rebeca, Rubio Coque, Juan José
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Universidad de León
Repositorio:BULERIA. Repositorio Institucional de la Universidad de León
OAI Identifier:oai:buleria.unileon.es:10612/26565
Acceso en línea:https://www.mdpi.com/2076-2607/13/7/1622
https://hdl.handle.net/10612/26565
https://doi.org/10.3390/ microorganisms13071622
Access Level:acceso abierto
Palabra clave:Biología
Verticillium wilt
Olive
Endophytic streptomycetes
Biocontrol
Antifungal compounds
Rapamycin
2414 Microbiología
2511.09 Microbiología de Suelos
2412 Inmunología
Descripción
Sumario:[EN] Verticillium wilt, caused by Verticillium dahliae, poses a significant threat to olive trees (Olea europaea L.). The isolation of endophytic Streptomyces strains from olive roots has led to the discovery of several strains showing strong antifungal activity against V. dahliae, as demonstrated through in vitro and small-scale soil experiments. Molecular analyses confirmed that strain OE54 belongs to Streptomyces iranensis. The main antifungal compound identified in this strain was rapamycin. Rapamycin displayed potent antifungal effects, notably inhibiting conidiospore germination (IC50 = 87.36 μg/mL) and the hyphal growth of V. dahliae, with a minimum inhibitory concentration (MIC50) of 3.91 ng/mL. Additionally, a second rapamycin-producing strain, OE57T, was isolated. Phenotypic and genotypic analyses indicated that OE57T represents a new species, which is proposed to be named Streptomyces lacaronensis sp. nov., with OE57T designated as the type strain (=DSM 118741T; CECT 31164T). The discovery of two endophytic rapamycin-producing Streptomyces strains residing within olive roots is especially notable, given the rarity of rapamycin production among microorganisms. These findings highlight the potential of rapamycin-producing Streptomyces strains in developing biofertilizers to manage V. dahliae and reduce the impact of Verticillium wilt on olive trees and other crops.